Titanium alloy has become an important aviation material due to the advantages of high strength, high corrosion resistance and the like. The use of the titanium alloy is of great significance for reducing the weight of an aircraft and upgrading the performances of the aircraft. Although the titanium alloy has good corrosion resistance, when the titanium alloy is in contact with aluminum alloy and alloy steel, the titanium alloy is prone to produce the contact corrosion and thus causes the failure under the synergic action of stress and environment.
The contact corrosion is galvanic corrosion, that is when dissimilar metals are in contact in a same medium, the dissolution rate of the metal with the lower potential is accelerated due to the different metal potentials, thereby causing the local corrosion in the contact position. The fundamental measure for controlling the contact corrosion is to lead the potentials of the dissimilar materials in contact to be close to each other and further reduce or eliminate the contact corrosion by reasonably selecting the material of a coating and appropriately carrying out surface modification and surface plating and coating treatment.
Although the studies in the prevention of the contact corrosion of the titanium alloy at home and abroad have obtained certain achievements, there are still certain problems existing in the current means, and the main problem is that the adopted coating is very easy to lose the protective effect under the synergic action of the environment and the stress, the conventional plated coating on the surface of the titanium alloy is very easy to peel off and lose the anti-corrosion role under the action of contact loads, and debris peeling off the coating can lead the parts in contact to form abrasive wear and further accelerate the failure rate of the parts. Therefore, the problem urgent to be solved for a large number of titanium alloy fasteners in the aircraft is the failure problem caused by the contact corrosion.